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  PrinterUSPTO Application #: 20070122223Title: Printer Abstract: A printer includes a platen, a feed roller, recording units, a pressure auxiliary roller that faces an outer peripheral surface of the platen and is disposed at a front position before the recording units in a feed direction so as to press the recording medium against the outer peripheral surface of the platen, a pressure unit including pressure rollers that face the outer peripheral surface of the platen and is disposed at a back position after the pressure auxiliary roller in the feed direction so as to press the recording medium against the outer peripheral surface of the platen with a pressing force larger than a pressing force of the pressure auxiliary roller, and a control unit that causes a circumferential speed of the feed roller to be temporarily slower than a circumferential speed of the platen. (end of abstract) Agent: Brinks Hofer Gilson & Lione - Chicago, IL, US Inventors: Kazutaka Suzuki, Hiroyuki Murayama USPTO Applicaton #: 20070122223 - Class: 400120020 (USPTO) Related Patent Categories: Typewriting Machines, Typing By Other Than Type-face Or Type-die, Thermal, Multicolor The Patent Description & Claims data below is from USPTO Patent Application 20070122223. Brief Patent Description - Full Patent Description - Patent Application Claims
[0001] This application claims the benefit of priority to Japanese Patent Application No. 2005-340639, filed on Nov. 25, 2005, which is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a printer, and particularly to a printer capable of being preferably used in a line thermal printer or an inkjet printer that prints on a recording medium, such as recording paper or the like, having a predetermined size, for example, a size of A4 or long roll paper with ink while pressing the recording medium against a roller-shaped platen. [0004] 2. Description of the Related Art [0005] In general, a printer, such as a line thermal printer or an inkjet printer, applies or thermally transfers ink onto a recording medium, such as roll paper or recording paper, and may be used as an output device of a computer. [0006] As shown in FIG. 8, for example, a printer 101 in the related art includes a roller-shaped platen 103, recording units 104, a feed roller 102, and a discharge roller 111. While applying tension to the recording medium 110 wound around the outer periphery of the platen, the roller-shaped platen 103 is rotated in the same direction as a feed direction FD of a recording medium 110. Each of the recording units 104 includes a thermal head or a recording head 104a, such as an ink nozzle. The feed roller 102 is disposed at a front position before the platen 103 in the feed direction FD so as to feed the recording medium 110, and the discharge roller 111 is disposed at a back position after the platen 103 in the feed direction FD so as to discharge the recording medium 110. [0007] In this case, four recording units 104 are provided in a circumferential direction of the platen 103 so as to correspond to four colors, such as yellow, magenta, cyan, and black (or overcoat). Further, the recording medium 110 is interposed between the recording head 104a of each recording unit 104 and the platen 103. Accordingly, when the feed roller 102 and the discharge roller 111 are rotated, the recording medium 110 is wound around the outer peripheral surface of the platen 103 and fed in the predetermined feed direction FD. As a result, each of the recording units 104 records desired letters or images on the recording medium 110 (see, for example, JP-A-2003-251840). [0008] However, the printer 101 in the related art does not include a unit for removing slack SS from the recording medium 110. Accordingly, as shown in FIG. 8, when the recording medium 110 does not come in close contact with the platen 103 and is fed with the slack SS, it is not possible to make the recording head 104a of each recording unit 104 appropriately come in contact with a portion of the recording medium 110 on which the slack SS occurs. As a result, it is not possible to record desired letters or images on the recording medium 110. [0009] In addition, according to the printer 101 in the related art, until the recording medium 110 is fed to the discharge roller 111, the recording medium 110 cannot come in close contact with the outer peripheral surface of the platen 103, as a result, the recording units cannot begin recording on the recording medium 110. SUMMARY [0010] An object of the invention is to provide a printer in which a recording medium can come in close contact with the surface of the platen. [0011] Further, it is another object of the invention to provide a printer that does not perform unnecessary feeding of the recording medium and makes the recording medium come in close contact with the platen from the leading end of the recording medium. [0012] Furthermore, it is another object of the invention to provide a printer in which each of the recording units can perform recording at a desired position on the recording medium even if the recording medium slides on the platen to remove slack from the recording medium. [0013] In order to achieve the above-mentioned objects, according to a first aspect of the invention, a printer includes a feed roller that feeds a recording medium in a predetermined feed direction, a roller-shaped platen that is rotated in the feed direction of the recording medium, recording units that face an outer peripheral surface of the platen and approach or recede from the platen so as to record desired letters or images on the recording medium, a pressure auxiliary roller that faces the outer peripheral surface of the platen at a front position before the recording units in the feed direction and presses the recording medium against the outer peripheral surface of the platen, a pressure unit that includes pressure rollers, pushing means, and moving means, and a control unit that makes a circumferential speed of the feed roller become temporarily slower than a circumferential speed of the platen when the pressure rollers press the recording medium against the platen. In this case, each of the pressure rollers is formed in the shape of a roller that has a diameter smaller than a maximum distance between each of the recording units and the platen, and faces the outer peripheral surface of the platen at a back position after the pressure auxiliary roller in the feed direction. Further, when the recording medium is provided in a predetermined gap between each pressure roller and the platen, the pushing means pushes the pressure rollers against the outer peripheral surface of the platen with a pressing force larger than a pressing force of the pressure auxiliary roller. In addition, when the pressure rollers are pressed against the outer peripheral surface of the platen, the moving means moves the pressure rollers from front positions to the back positions in the feed direction of the recording medium in conjunction with the rotation of the platen. [0014] According to the first aspect of the invention, the recording medium comes in close contact with the platen, and the platen and the feed roller for feeding the recording medium apply tension to the recording medium so as to remove the slack from the recording medium. As a result, it is possible to make the recording medium come in close contact with the platen. [0015] According to a second aspect of the invention, in the printer according to the first aspect of the invention, the control unit may temporarily stop the platen and temporarily rotate the feed roller in a reverse direction. [0016] According to the second aspect of the invention, since the recording medium is temporarily stopped to apply tension to the recording medium, it is possible to make the recording medium come in close contact with the platen from the leading end of the recording medium without over feeding the recording medium. Further, since the platen is stopped and the feed roller 2 is rotated in the reverse direction, it is possible to more quickly remove the slack from the recording medium as compared to when the feed roller and the platen are rotated in the same direction and the slack is removed by using a difference between the rotational speeds thereof. [0017] According to a third aspect of the invention, in the printer according to the first or the second aspect of the invention, until each of the recording units begins to perform recording, the control unit may make the circumferential speed of the feed roller be slower than the circumferential speed of the platen. Further, after each of the recording units begins to perform the recording, the control unit may make the circumferential speed of the feed roller be equal to the circumferential speed of the platen. [0018] According to the third aspect of the invention, after each of the recording units begins to perform the recording, the recording medium does not perform a sliding motion, which is performed to apply tension to the recording medium, on the outer peripheral surface of the platen. For this reason, the recording units can perform the recording at a desired position on the recording medium. BRIEF DESCRIPTION OF THE DRAWINGS [0019] FIG. 1 is a front view of a printer according to an embodiment of the invention as seen in an axial direction of a platen; [0020] FIG. 2 is a perspective view showing the printer of FIG. 1. Elements are mirror symmetric with respect to the platen, and only elements on one side of the platen in the axial direction of the platen are shown; and [0021] FIG. 3 is a perspective view of a ring gear of FIG. 2; Continue reading... Full patent description for Printer Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Printer patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Printer or other areas of interest. ### Previous Patent Application: Platen roller holding structure Next Patent Application: Method and apparatus for marking workpieces Industry Class: Typewriting machines ### FreshPatents.com Support Thank you for viewing the Printer patent info. IP-related news and info Results in 3.57113 seconds Other interesting Feshpatents.com categories: Daimler Chrysler , DirecTV , Exxonmobil Chemical Company , Goodyear , Intel , Kyocera Wireless , |
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